This invention relates to electrical terminal boards and particularly to modular terminal boards made up of interlocking sections.
Terminal blocks or boards are currently available in a variety of sizes and are used in applications ranging from low to utility voltages. Such boards may be either one-piece, sectional or modular construction and are also available in a single or double row construction.
A variety of top (above the board) and bottom (below the board) hardware is available to accommodate specific wiring conditions and installations. For example, contacts are available with screws for attaching wire lug assemblies, contacts are available with screws to clamp a bare conductor, and contacts are available in a rectangular tubular form wherein the conductors are retained either by a direct screw connection or a clamp connection. Contacts may also include "fast-on" terminals for quick connections or the contacts can "feed-through" a block, and the feed through unit may have solder tabs, fast-on tabs or even screw tabs. Others have open spaces between the barriers for ease of installation but may require covers. Most blocks utilize marking strips for circuit identification purposes.
Terminal boards or blocks are generally either of a one-piece or sectional construction. The one-piece units are usually molded in long lengths and cut to a specified circuit length. In some cases, they are molded to a specific length. Spacing between circuits is fixed as is electrical rating. In the sectional construction, units are assembled in multiples to suit a customer's requirements. Most sectional blocks require end mounts to complete the structure. This construction usually requires channel mounting for additional strength and support. Electrical hardware in both constructions can be quite varied, but the spacings between circuits are fixed requiring different moldings to accommodate different ratings.
The present invention proposes a modular unit which utilizes the same molding throughout a predetermined range but permits varying the spacing and therefore the electrical rating according to need. With a range of spacings, the user can accommodate his power wiring, control wiring and signal wiring. The terminal board as described hereinafter includes contacts which clamp the section modules together and which do not require an end section or retainer channel. The prior art is represented by U.S. Pat. No. 3,824,553 to Glover et al which discloses modular connectors mounted on a track and including matching tab portions and indents for interlocking the modules. A channel is located along the side of the modules for receiving and retaining a marker strip which acts to tie the modules together as well as operating as an identification strip. In contrast, the contact strip of the present invention serves to connect paired modules, is a connector and contact strip in combination oriented along a different axis.
Other prior art of general interest include U.S. Pat. Nos. 2,922,139, 3,019,408 and U.S. Pat. No. Re. 25,446 to G. Ustin as well as U.S. Pat. Nos. 3,201,747 to L. Blanchet, 3,121,051 to A. B. Clewes and 3,245,029 to J. Piperato.